(2) put together PHP scripts that, amongst other things, read and write UEF files and translate them to the extended TZX (which is 'TSX').

Potentially of help to real machine users, here, such TSXs are supported by at least TZXDuino and Maxduino.

I have not used these tools so cannot comment on their fidelity. I discovered the sequence of events only today: I was not involved and so cannot supply much in the way of further exposition. But it's another route, albeit tortuous, for using content available as UEF with a real machine, so I thought I'd repost.